Recording instrument



March 21, K EN E RECORDING INSTRUMENT Filed July 20, 1958 C :mmQ r w h noc r e .t v m T lm .6 U H K Patented UNITED STATES 563K111 ROC PATENTOFFICE RECORDING INSTRUMENT ration of New York Application July 20,1938, Serial No. 220,403 In Germany July 30, 1937 3 Claims.

My invention relates to recording instruments and concerns particularlyimproved marking arrangements for such instruments and methods forproducing marking members.

It is an object of my invention to provide a marking arrangement for arecorder which overcomes friction by eliminating contact between themarking member and the moving chart.

It is a further object of my invention to provide a marking arrangementwhich may be utilized with a highly sensitive instrument and whichproduces clear, legible records.

It is also an object of my invention to provide a recording instrumentcombining the advantages of ink type and spark type recorders.

Other and further objects and advantages will become apparent as thedescription proceeds.

The invention may be understood more readily from the following detaileddescription when considered in connection with the accompanying drawing,and those features of the invention which are believed to be novel andpatentable will be pointed out in the claims appended hereto. In thedrawing Figure 1 is a schematic diagram partially in perspectiverepresenting one embodiment of my invention. Figure 2 is a view of across section 'of the marking receptacle of Figure 1 cut by theplanet-2', and Figure 3 is a fragmentary view of a longitudinal sectionof the marking receptacle cut by plane 33' indicated in Figure 2, andillustrating the method of manufacturing a marking receptacle. Likereference characters are utilized throughout the drawing to designatelike parts.

In Figure 1 a sensitive recording instrument is represented by itsmoving element I I, which may be a current carrying coil, for example,and is mounted upon a shaft 12 co-operating with bearings, not shown.The shaft l2 carries also a pointer arm l3 at the end of which issupported a marker H in the form of a receptacle for suitable markingmaterial, such as ink. The ink receptacle I4 is in the form of a smalltapered glass or a bottle having a filling mouth I5 at the upper end andan orifice H5 at the lower tapered end for depositing marking material.In the lower tapered end of the receptacle M a re-entrant wall or hollowbulb i1 is provided having an opening l8, the edge of which is adjacentand substantially within the edge IQ of the lower end of the receptacle"(see Figure 3). The wall of the inner bulb I1 'and the portion of theouter wall of the receptacle I4 adjacent the edges of the openings I8and 19 together form a substantially annular orifice represented bynumeral 16 in Figure 1. I have found the operation to be improved byhaving the edge of the opening [8 slightly higher than the edge IQ ofthe receptacle ll. The bulb I! may be secured by means of rods .20 (seeFigure 2) extending to the outer wall of the receptacle H.

Means are provided in the hollow space within the re-entrant wall orbulb I1 to produce repeatedly sudden expansion of the air within thehollow space, for example, by ionization. Such means may consist of apair of electrodes 2| and 22 projecting into the hollow space .withinthe bulb H. A pair of conductors 23 and 24 are provided which areconnected to the electrodes 2| and 22 at one end and are carried alongthe arm l3 to a suitable source of current. To prevent interference withthe deflection of the coil H a pair of loosely and oppositely woundhelices or spirals 25 and 26 may be provided through which the wires 23and 24 are connected to a suitable electric energizing circuit. Theenergizing circuit may consist of a source of current such as acomparatively high voltage battery 21 in series with which anintermittent make-and-break contactor 28 is provided. The make-and-breakcontactor 28 may take the form of a commutator driven by a constantspeed motor 29.

The receptacle l 4 for marking material may be composed of a suitablenon-corroding viscous material which is rigid at normal temperatures andmay be softened at elevated temperatures for the purpose ofmanipulation, such as glass, for example. The receptacle H may be blownfrom a globule of glass which has been inflated and drawn out to atapered point approximately in the shape shown. Thereupon, the neck 30may be formed by softening the material and pressing inward as thereceptacle is being rotated in accordance with the common practice knownto glass blowers. Likewise, the filling mouth I5 may be formed in theupper end of the receptacle in the usual manner after breaking away fromthe glass-blowers tube. The re-entrant wall or hollow bulb ll may beformed by sealing of! the lower end of the receptacle by fusion, forexample, and while the material is soft, blowing the end of thereceptacle inward, for example, by slipping a suction tube over thefilling mouth l5. v While the material is sufficiently soft, theelectrodes 2| and 22 may be inserted in place. If the electrodes 2| and22 seal suitably to the glass it may not be necessary to provide therods 20 for holding the bulb H in place. The orifice i6 is formed afterthe wall 11 has been blown inward by cutting oil the lower end of thereceptacle l4. This may be done by fusion or any other suitable process.Preferably the edges of the material are so cut as to lie along the cone3| represented in Figure 3. This makes the edges of the opening I! ofthe bulb I! slightly higher than the edges 19 of the main walls of thereceptacle H, but substantially concentric therewith.

The method of operation of the apparatus will be apparent from theforegoing description as the rotation of the commutator 28 will causethe application of voltage repeatedly to the electrodes 2| and 22,thereby repeatedly ionizing the air in a. hollow space within the bulbl1. Each time the air is ionized it expands suddenly causing theexpansion of ink or other marking material which has collected at theorifice I6 and across the opening H3 in the bulb H and which is heldthere by capillary attraction and surface tension. It will be understoodthat the orifice I6 is carried adjacent the surface of a record chart.not shown, and the ink expelled from the orifice I6 is deposited on therecord chart in fine, rapidly drying dots which may be placed very closetogether upon the record chart so as to form a substantially continuousrecord curve.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention together with theapparatus which I now consider to represent the best embodiment thereofbut I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent oi. theUnited States, is:

1. A marking arrangement ior recqrgll mnents Z'I u::

oi sparkmelectrodes, said receptacle a ng ari'an fiular orifice andhaving a re-entrant wall forming a hollow space, the inner edge of saidannular orifice being set in from the outer. edge of said annularorifice and forming an outlet opening for said hollow space, saidelectrodes extending into said hollow space and forming a spark gaptherein.

2. A marking arrangement for recording instruments comprising areceptacle for marking material with an opening therein, a bulb withinsaid receptacle having an opening adjacent and substantially within saidreceptacle opening ing such end of the receptacle, blowing it inward toform a hollow bulb within the receptacle, fastening the bulb within thereceptacle and cutting ofl the material at the end of the receptacle andthe bulb to form an annular orifice in the receptacle.

KURT GENSCI-IMER.

